Use more renewable resources (solar, wind, hydroelectric, etc) and fewer fossil fuels (coal, petroleum, and natural gas), since fossil fuels produce a lot of carbon dioxide
Eat less livestock (farm animals, such as cows, produce a lot of methane and waste) and possibly become vegetarian/vegan
Decrease deforestation (trees absorb carbon dioxide and release oxygen)
Recycle/reuse more items to decrease the amount of trash in oceans, forests, and other ecosystems
